The objective of this project was to develop Bulk Production Methods for culturing gram amounts of mammalian cells, particularly nonneoplastic and human diploid cells, that require a surface on which to attach and divide. In a new commercially available culture vessel, human diploid fibroblasts grew well, provided optimal physiologic conditions were maintained by means of complete medium renewal(s) as indicated by glucose utilization. A mixture of pancreatin-versene was found most successful for recovering Phase II WI-38 cells in excellent physiologic condition.